H.J. Trodahl, C.E.A. Grigorescu, A. Bittar, F.Budde, B.J. Ruck, S. Granville, G.V.M. Williams, SEM and Raman studies of annealed nanocrystalline GaN and amorphous GaN:O, Journal of Non-Crystalline Solids, 352/9-20 (2006) 1282-1285

Title: SEM and Raman studies of annealed nanocrystalline GaN and amorphous GaN : O

Abstract: We report annealing studies of thin films of GaN and GaN:O prepared by ion assisted deposition. As-prepared films of stoichiometric tetrahedrally bonded GaN form nanocrystalline networks, but amorphous networks result with the inclusion of more than 10 at.% of oxygen. The annealed nc-GaN films show an increased average crystallite size, though even after a 700 degrees C anneal the crystals are no larger than about 10 nm. Annealed a-GaN:O films remain amorphous even after a 700 degrees C anneal, after which they display a weak photoluminescence.

Key words: III-V semiconductors; vapor phase deposition; SEM; luminescence; Raman spectroscopy; short-range order